opensolaris man page for setgroups

getgroups(2)							   System Calls 						      getgroups(2)

NAME
       getgroups, setgroups - get or set supplementary group access list IDs

SYNOPSIS
       #include <unistd.h>

       int getgroups(int gidsetsize, gid_t *grouplist);

       int setgroups(int ngroups, const gid_t *grouplist);

DESCRIPTION
       The getgroups() function gets the current supplemental group access list of the calling process and stores the result in the array of group
       IDs specified by grouplist. This array has gidsetsize entries and must be large enough to contain the entire  list.  This  list	cannot	be
       larger than NGROUPS_UMAX. If gidsetsize equals 0, getgroups() will return the number of groups to which the calling process belongs without
       modifying the array pointed to by grouplist.

       The setgroups() function sets the supplementary group access list of the calling process from the array of group  IDs  specified  by  grou-
       plist. The number of entries is specified by ngroups and can not be greater than NGROUPS_MAX.

RETURN VALUES
       Upon  successful  completion, getgroups() returns the number of supplementary group IDs set for the calling process and setgroups() returns
       0. Otherwise, -1 is returned and errno is set to indicate the error.

ERRORS
       The getgroups() and setgroups() functions will fail if:

       EFAULT	 A referenced part of the array pointed to by grouplist is an illegal address.

       The getgroups() function will fail if:

       EINVAL	 The value of gidsetsize is non-zero and less than the number of supplementary group IDs set for the calling process.

       The setgroups() function will fail if:

       EINVAL	 The value of ngroups is greater than {NGROUPS_MAX}.

       EPERM	 The {PRIV_PROC_SETID} privilege is not asserted in the effective set of the calling process.

USAGE
       Use of the setgroups() function requires the {PRIV_PROC_SETID} privilege.

ATTRIBUTES
       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |getgroups() is Standard.	   |
       +-----------------------------+-----------------------------+
       |MT-Level		     |Async-Signal-Safe 	   |
       +-----------------------------+-----------------------------+

SEE ALSO
       groups(1), chown(2), getuid(2), setuid(2), getgrnam(3C), initgroups(3C), attributes(5), privileges(5), standards(5)

SunOS 5.11							    8 Sep 2006							      getgroups(2)